Methane oxidation pathways

Methane oxidation pathways at oxic-anoxic boundaries in lakes

Methane emissions from lakes and reservoirs to the atmosphere contribute significantly to the global methane cycle. Lakes and reservoirs have so far not been part of global budgets but they could contribute up to 10% to the atmospheric flux. Such estimates are poorly constrained because methane is produced at highly variable rates, and it can be oxidized in the sediment and in the water column. Over the last years, several pathways of methane oxidation via sulfate, nitrate or iron reduction have been discovered.
In this project we will address the research questions which pathways of methane oxidation are operating at different redox environments in lakes and which fraction of methane is transformed by different electron acceptors? We will perform field studies in four selected lakes in Switzerland, Spain, Central Africa and Western Canada. We will combine high-resolution profiling and sampling techniques, stable isotope and biomarker analysis, and reaction-transport modeling in order to provide general insights and reference data for improved global estimates.

Collaboration

• Carsten Schubert, Eawag
• Lee Bryant, Virginia Tech, USA / Eawag
  
• Marcel Kuypers, MPI Bremen